Table of Contents
Advertisement
SUBB
(B) – (M) ⇒ B
Operation:
Description:
Subtracts the content of memory location M from the content of accumu-
lator B and places the result in B. For subtraction instructions, the C sta-
tus bit represents a borrow.
Condition Codes and Boolean Formulas:
S
–
N:
Z:
V:
C:
Addressing Modes, Machine Code, and Execution Times:
Source Form
SUBB # opr8i
SUBB opr8a
SUBB opr16a
SUBB oprx0_xysp
SUBB oprx9 , xysp
SUBB oprx16 , xysp
SUBB [D ,xysp ]
SUBB [ oprx16,xysp ]
MOTOROLA
6-194
Subtract B
X
H
I
N
Z
∆
∆
–
–
–
Set if MSB of result is set; cleared otherwise.
Set if result is $00; cleared otherwise.
X7 • M7 • R7 + X7 • M7 • R7
Set if a two's complement overflow resulted from the operation;
cleared otherwise.
X7 • M7 + M7 • R7 + R7 • X7
Set if the value of the content of memory is larger than the value of
the accumulator; cleared otherwise.
Address Mode
IMM
DIR
EXT
IDX
IDX1
IDX2
[D,IDX]
[IDX2]
INSTRUCTION GLOSSARY
V
C
∆
∆
Object Code
C0 ii
D0 dd
F0 hh ll
E0 xb
E0 xb ff
E0 xb ee ff
E0 xb
E0 xb ee ff
SUBB
Cycles
Access Detail
1
P
3
rfP
3
rOP
3
rfP
3
rPO
4
frPP
6
fIfrfP
6
fIPrfP
CPU12
REFERENCE MANUAL
Advertisement
Table of Contents
